1. Field of the Invention
The present invention relates to a sintering system, a method of sintering a die and a die. More particularly, the invention relates to a laser sintering system, a method of using a laser beam sintering a die and a die sintered by a laser beam.
2. Description of the Prior Art
Generally, the semiconductor fabrication process could be sketchily divided into wafer fabrication process, wafer probe process, wafer packaging process and wafer test process. After finishing the fabrication process and the probe process, the wafer will undergo the wafer packaging process.
Before beginning the wafer packaging process, the wafer has to be sawed into dies by saw equipment. The purpose of the process is to separate the dies of the wafer. Using a die saw to saw the wafer during the process would obtain the individual dies.
The die saw is elaborate equipment. Since the distance between dies is quite small, usually about 2 mil, and the die is quite brittle, the die needs to be separated from each other by a diamond saw blade applying grinding procedure.
Due to the diamond saw blade during the wafer dicing process, the edge of each sawed die becomes serrate. As shown in FIGS. 1 to 3, the dies of prior art have serrate edges. The die 1 and die 2 have no coating layers on their first surface and second surface. Die 3 and die 4 have coating layers on their first surface and second surface. Since the integrated circuit fabricated by wafers is made of silicon single crystal, the serrate cracks of the dies 1,2,3,4 of prior art expand easily. These serrate cracks will cause the damage of the integrated circuit and decrease the yield of the product.
Therefore, there is a demand to provide a die having a smooth edge avoiding the damage of the integrated circuit and increasing the yield of the product. Furthermore, it is more demanding to provide an apparatus and a method of smoothing the surface of the die.
In view of the disadvantage of the die having a serrate edge of the prior art, the present invention provides a die having a smooth edge avoiding the cracks of the die and increasing the yield of the back-end process. In order to provide a die having a smooth edge, the present invention further provides a laser sintering system and a laser sintering method of smoothing the edge of the die.
An object of the present invention is to provide a system smoothing the edge of a die. For this purpose, the present invention provides a laser sintering system of smoothing a serrate edge of a die. The laser sintering system comprises a laser generator for generating a laser beam and a movable carriage for carrying the die. The laser beam sinters the serrate edges of the dies into smooth edges.
In accordance with an embodiment of the laser sintering system of the present invention, the first surface and the second surface of the die respectively have a coating layer.
In accordance with an embodiment of the laser sintering system of the present invention, the laser beam is a CO2 laser beam, a Nd-YAG laser or an Excimer laser beam.
In accordance with an embodiment of the laser sintering system of the present invention, the laser sintering system further comprises a laser control unit for transmitting the first signal to the laser generator; a server engine for moving said carriage and a computer controller. The computer controller transmits the second signal to the laser control unit and the third signal to the servo engine.
Another object of the present invention is to provide a method of sintering a die having a serrate edge. The method comprises the following steps: providing a die and using a laser beam sintering the serrate edge of the die into smooth edges.
In accordance with an embodiment of the method of sintering the die, the first surface and the second surface of the die respectively have a coating layer.
In accordance with an embodiment of the method of sintering the die, the laser beam is a CO2 laser beam, a Nd-YAG laser beam or an Excimer laser.
Still another purpose of the present invention is to provide a die having a smooth edge sintered by the laser beam.
In accordance with an embodiment of the die, the first surface and the second surface of the die respectively have a coating layer.
In accordance with an embodiment of the die, the laser beam is a CO2 laser beam, a Nd-YAG laser beam or an Excimer laser.